The narrowest street in Paris.

The fairy tale castle of the “fairy-tale king,” this was also the inspiration for Disney’s “Sleeping Beauty.”

A fearsome dragon clings to a corner of Munich's city hall.

Ancient snack bar of the Roman Empire re-opened.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

This curious, round temple is the oldest still-standing marble building in Rome.

The ruins of a medieval monastery named after a type of tree.

This ancient Irish tower could easily have stood in for Rapunzel's prison.

These caves secretly held national treasures during World War II.

These artifacts were discovered during the construction of the airport, with some dating back to the Neolithic period.

Legend says this sacred tree was a gift from goddess Athena.

Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

The "Great Sewer" of ancient Rome is one of the oldest sewer systems in the world, and is still in use.

This towering church is home to a world-famous organ and a treasure trove of medieval art.

Tucked in the back of a flower shop, its collection details the fascinating history of the Netherlands's iconic symbol.

This cheese shop also houses a museum devoted to Dutch dairy.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

A man's head is enshrined beneath a statue near the first building constructed for the modern Olympic Games.

A Byzantine-era church hidden in a wooded area below the Acropolis.

The Cycladic architecture makes this Athens neighborhood feel like an island paradise hidden in the shadow of the Acropolis.

An ancient octagonal weather station named for the eight Greek gods of wind.

This mystical orb covered in strange symbols is thought to have been used in ancient Greek magical rituals.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

A turn of the century building boasting some of the most beautiful art nouveau architecture in Prague.